1. Field of the Invention
The present invention relates to a data communication terminal for conducting data communications by use of a communication network where accounting is carried out according to an amount of transferred data, and a method thereof, and a computer readable recording medium that stores a program including commands which instruct a computer to act as such a data communication terminal.
2. Description of the Related Art
In the prior art, in the accounting methods of communication charges in data communications, there have been an accounting method according to connection time, and an accounting method according to the transmitted/received data amount, and communication charges by these respective methods are accumulated, and charges are demanded to users periodically, for example, an monthly basis or the like.
In order to avoid such a case where a monthly bill for such higher charges as users do not forecast should not be made, connection time or the transmitted/received data amount is calculated at a terminal device of each user, and the accumulative charges are calculated according to the accounting method, and the charges at the moment are displayed at necessity so that each user can see his charges at sight.
A technique that gives a warning to a user in the case when the charge limit set by the user is exceeded is well known. Thereby, a user who has been given such a warning may keep from using connections, and accordingly unexpectedly high charges may be avoided.
In the case of the accounting method according to the transmitted/received data amount, when the amount of data to be transmitted/received continuously is small as in text data, the charges appear smaller than in the case of the accounting method according to connection time, and hence the accounting method according to the transmitted/received data amount is convenient. However, when the amount of data to be transmitted/received continuously is large as in downloading image data, charges will become higher. Especially, in the case of using an extremely high speed communication line, users may transmit/receive a large amount of data without noticing, and as a result, communication charges will become enormous in a short time. If the transmitted/received data is really necessary for a user, then it is all right; on the other hand, if data is unnecessary or valueless, then a user feels it very wasteful, and the cost performance of communications as a whole will be deteriorated, which has been a problem seen with the prior art.
In other words, in the prior art mentioned above, users keep from using further connections when the preset limit amounts are exceeded, so that unexpectedly high charges may be prevented from being issued to users. However, the prior art has failed to improve communication cost performance by reducing receiving and sending of unnecessary data, which has been the problem with the prior art.